170 Dr. Thomas Thomson* s Experiments 



is done, the grand end of biography is marred. But, while 

 the imperfections of the subject of our memoir have been 

 exhibited, we trust that the great benefits he conferred 

 upon science have been detailed in such characters as may 

 render them worthy of imitation ; and thus, though he no 

 longer resides among us, that rivals may be incited to start 

 from the point where his labours ceased, and to act in sub- 

 servience to the growing wants of society. 



Article II. 



Experiments on the Absorption of Air hy Water. By Thomas 

 Thomson, M.D., F.R.S.L. & E., &c., Regius Professor 

 of Chemistry in the University of Glasgow. 



Not being aware of any direct experiments upon the 

 subjects mentioned in the title of this paper, I amused 

 myself, during the early part of the present summer, in 

 making a few trials to satisfy myself whether the opinions 

 at present entertained on these subjects were entitled to 

 confidence. I shall state my experiments on each of the 

 different subjects in order. 



I. — Of the quantity of Air contained in Clyde water. 



The city of Glasgow is supplied with water pumped out 

 of the river Clyde, and conveyed to reservoirs in the higher 

 parts of the town, from which it is conveyed in pipes to 

 every house. As one of these pipes supplies my laboratory, 

 I have only to turn a stock cock to obtain as much river 

 water as I have occasion for. 



1. I filled a retort, the belly of which held 168 cubic 

 inches, and its throat and beak 75 cubic inches more, with 

 river water, plunged the beak into a water trough, and 

 placed a small inverted jar full of water over the extremity 

 of the beak. I then boiled the water till it ceased to give 

 out any air. I collected 5*25 cubic inches of air. Baro- 

 meter at 29'5 inches. Thermometer 53°. 



In this experiment 168 cubic inches of water gave out 

 5*23 cubic inches (making the requisite corrections) of air, 

 supposing the barometer at 30 inches and the thermometer 

 at 60°. The 75 cubic inches which filled the throat and beak 



